Trader consensus on Polymarket has locked in a 100% implied probability for a highest temperature of exactly 10°C at Toronto Pearson International Airport on April 1, backed by Environment Canada's official hourly observations showing that precise maximum amid persistent cloud cover and northerly winds gusting to 20 km/h, which capped daytime heating after an overnight start near 9°C. This aligns with pre-event forecasts from the Canadian Meteorological Centre's models, which projected highs near 10°C under a cool air mass influenced by a lingering high-pressure ridge over the Great Lakes region—consistent with early April climatology where average highs hover around 11°C but variability from synoptic patterns often yields such outcomes. With data now verified from the airport's automated sensors, no realistic scenarios challenge this positioning barring rare post hoc revisions from quality control audits.